/*******************************************************************************
 * Copyright (c) 2000, 2015 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     James Blackburn (Broadcom Corp.) - Bug 294628 multiple selection
 *******************************************************************************/
package org.eclipse.ui.dialogs;

import org.eclipse.core.runtime.Assert;
import org.eclipse.jface.preference.PreferenceDialog;
import org.eclipse.jface.viewers.ISelectionProvider;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.window.IShellProvider;
import org.eclipse.jface.window.SameShellProvider;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.actions.SelectionProviderAction;
import org.eclipse.ui.internal.IWorkbenchHelpContextIds;
import org.eclipse.ui.internal.WorkbenchMessages;
import org.eclipse.ui.internal.dialogs.PropertyDialog;
import org.eclipse.ui.internal.dialogs.PropertyPageContributorManager;

/**
 * Standard action for opening a Property Pages Dialog on the currently selected
 * element.
 * <p>
 * This class may be instantiated; it is not intended to be subclassed.
 * </p>
 * <p>
 * Generally speaking, this action is useful in pop-up menus because it allows
 * the user to browse and change properties of selected elements. When
 * performed, the action will bring up a Property Pages Dialog containing
 * property pages registered with the workbench for elements of the selected
 * type.
 * </p>
 * <p>
 * Although the action is capable of calculating if there are any applicable
 * pages for the current selection, this calculation is costly because it
 * require searching the workbench registry. Where performance is critical, the
 * action can simply be added to the pop-up menu. In the event of no applicable
 * pages, the action will just open an appropriate message dialog.
 * </p>
 *
 * @noextend This class is not intended to be subclassed by clients.
 */
public class PropertyDialogAction extends SelectionProviderAction {
	/**
	 * Provides the shell in which to open the property dialog.
	 */
	private IShellProvider shellProvider;

	/**
	 * The id of the page to open up on.
	 */
	private String initialPageId;

	/**
	 * Creates a new action for opening a property dialog on the elements from the
	 * given selection provider.
	 *
	 * @param shell    the shell in which the dialog will open
	 * @param provider the selection provider whose elements the property dialog
	 *                 will describe
	 * @deprecated use PropertyDialogAction(IShellProvider, ISelectionProvider)
	 */
	@Deprecated
	public PropertyDialogAction(Shell shell, ISelectionProvider provider) {
		this(new SameShellProvider(shell), provider);
	}

	/**
	 * Creates a new action for opening a property dialog on the elements from the
	 * given selection provider.
	 *
	 * @param shell    provides the shell in which the dialog will open
	 * @param provider the selection provider whose elements the property dialog
	 *                 will describe
	 * @since 3.1
	 */
	public PropertyDialogAction(IShellProvider shell, ISelectionProvider provider) {
		super(provider, WorkbenchMessages.PropertyDialog_text);
		Assert.isNotNull(shell);
		this.shellProvider = shell;
		setToolTipText(WorkbenchMessages.PropertyDialog_toolTip);
		PlatformUI.getWorkbench().getHelpSystem().setHelp(this, IWorkbenchHelpContextIds.PROPERTY_DIALOG_ACTION);
	}

	/**
	 * Returns whether the provided selection has pages registered in the property
	 * page manager.
	 *
	 * @param object
	 * @return boolean
	 */
	private boolean hasPropertyPagesFor(IStructuredSelection object) {
		return PropertyPageContributorManager.getManager().getApplicableContributors(object).size() != 0;
	}

	/**
	 * Returns whether this action is actually applicable to the current selection.
	 * If this action is disabled, it will return <code>false</code> without further
	 * calculation. If it is enabled, it will check with the workbench's property
	 * page manager to see if there are any property pages registered for the
	 * selected element's type.
	 * <p>
	 * This method is generally too expensive to use when updating the enabled state
	 * of the action on each selection change.
	 * </p>
	 *
	 * @return <code>true</code> if the selection is not empty and there are
	 *         property pages for the selected element, and <code>false</code>
	 *         otherwise
	 */
	public boolean isApplicableForSelection() {
		if (!isEnabled()) {
			return false;
		}
		return isApplicableForSelection(getStructuredSelection());
	}

	/**
	 * Returns whether this action is applicable to the current selection. This
	 * checks that the selection is not empty, and checks with the workbench's
	 * property page manager to see if there are any property pages registered for
	 * the selected element's type.
	 * <p>
	 * This method is generally too expensive to use when updating the enabled state
	 * of the action on each selection change.
	 * </p>
	 *
	 * @param selection The selection to test
	 * @return <code>true</code> if the selection is of not empty and there are
	 *         property pages for the selected element, and <code>false</code>
	 *         otherwise
	 */
	public boolean isApplicableForSelection(IStructuredSelection selection) {
		return !selection.isEmpty() && hasPropertyPagesFor(selection);
	}

	@Override
	public void run() {

		PreferenceDialog dialog = createDialog();
		if (dialog != null) {
			dialog.open();
		}
	}

	/**
	 * Create the dialog for the receiver. If no pages are found, an informative
	 * message dialog is presented instead.
	 *
	 * @return PreferenceDialog or <code>null</code> if no applicable pages are
	 *         found.
	 * @since 3.1
	 */
	public PreferenceDialog createDialog() {
		if (getStructuredSelection().isEmpty())
			return null;

		return PropertyDialog.createDialogOn(shellProvider.getShell(), initialPageId, getStructuredSelection());
	}

	@Override
	public void selectionChanged(IStructuredSelection selection) {
		setEnabled(!selection.isEmpty());
	}
}
